Gaius Julius Caesar Germanicus was the third son of Germanicus (nephew of Tiberius) and Agrippina the elder and was born at Antium in AD 12.

It was during his stay with his parents on the German frontier, when he was between two and four, that his miniature versions of military sandals (caligae), caused the soldiers to call him Caligula, 'little sandal'. It was a nickname which remained with him for the rest of his life.

When he was in his late teens his mother and elder brothers were arrested and died horribly due to the plotting of the praetorian prefect Sejanus. No doubt the horrendous demise of his closest relatives must have had a profound effect on the young Caligula.
Attempting to rid himself of Gaius, Sejanus, under the belief that he may be a potential successor, went too far and was alas arrested and put to death by orders of emperor Tiberius in AD 31.
In the same year Caligula was invested as a priest.
From AD 32 onwards he lived on the island of Capreae (Capri) in the emperor's lush residence and was appointed joint heir with Tiberius Gemellus, son of Drusus the younger. Though by that time Tiberius was in old age and, with Gemellus still a child, it was obvious that it would be Caligula who would truly inherit the power for himself.
By AD 33 he was made quaestor, though was given no further administrative training at all.

Caligula was very tall, with spindly legs and a thin neck. His eyes and temples were sunken and his forehead broad and glowering. His hair was thin and he was bald on top, though he had a hairy body (during his reign it was a crime punishable by death to look down on him as he passed by, or to mention a goat in his presence).

There were rumours surrounding the death of Tiberius. It is very likely that the 77 year-old emperor did simply die of old age.
But one account tells of how Tiberius was thought to have died. Caligula drew the imperial signet ring from his finger and was greeted as emperor by the crowd. Then however news reached the would-be emperor that Tiberius had recovered and was requesting food be brought to him. Caligula, terrified at any revenge by the emperor returned from the dead, froze on the spot. But Naevius Cordus Sertorius Macro, commander of the praetorians, rushed inside and smothered Tiberius with a cushion, suffocating him.

In any case, with the support of Macro, Caligula was immediately hailed as princeps ('first citizen') by the senate (AD 37). No sooner did he get back to Rome the senate bestowed upon him all the powers of imperial office, and - declaring Tiberius' will invalid - the child Gemellus was not granted his claim to the joint reign.
But it was above all the army which, very loyal to the house of Germanicus, sought to see Caligula as sole ruler.

Caligula quietly dropped an initial request for the deification of the deeply unpopular Tiberius.
All around there was much rejoicing at the investment of a new emperor after the dark later years of his predecessor.
Caligula abolished Tiberius' gruesome treason trials, paid generous bequests to the people of Rome and an especially handsome bonus to the praetorian guard.

There is an amusing anecdote surrounding Caligula's accession to the throne. For he had a pontoon bridge built leading across the sea from Baiae to Puzzuoli; a stretch of water two and a half miles long. The bridge was even covered with earth. With the bridge in place, Caligula then, in the attire of a Thracian gladiator, mounted a horse a rode across it. Once at one end, he got off his horse and returned on a chariot drawn by two horses. These crossings are said to have lasted for two days.
The historian Suetonius explains that this bizarre behaviour was down to a prediction made by an astrologer called Trasyllus to emperor Tiberius, that 'Caligula had no more chance of becoming emperor than of crossing the bay of Baiae on horseback'.

Then, only six months later (October AD 37), Caligula fell very ill. His popularity was such that his illness caused great concern throughout the entire empire.
But, when Caligula recovered, he was no longer the same man. Rome soon found itself living in a nightmare.
According to the historian Suetonius, Caligula since childhood suffered from epilepsy, known in Roman times as the 'parliamentary disease', since it was regarded as an especially bad omen if anyone had a fit while public business was being conducted - Caligula's very distant cousin, Julius Caesar, also suffered occasional attacks. This, or some other cause, violently affected his mental state, and he became totally irrational, with delusions not only of grandeur but also of divinity.
He now suffered from a chronic inability to sleep, managing only few hours of sleep a night, and then suffering from horrendous nightmares. Often he would wander through the palace waiting for daylight.

Caligula had four wives, three of them during his reign as emperor and he was said to have committed incest with each of his three sisters in turn.

In AD 38 Caligula put to death without trial his principal supporter, the praetorian prefect Macro. The young Tiberius Gemellus suffered the same fate.
Marcus Junius Silanus, the father of the first of Caligula's wives was compelled to commit suicide.
Caligula became ever more unbalanced. Seeing the emperor ordering an altar to be built to himself was worrying to Romans. But to propose that statues of himself should be erected in synagogues was more than merely worrying. Caligula's excesses knew no bounds, and he introduced heavy taxation to help pay for his personal expenditure. He also created a new tax on prostitutes and is said to have opened a brothel in a wing of the imperial palace.
All these occurrences naturally alarmed the senate. By now there was no doubt that the emperor of the civilized world was in fact a dangerous madman.
Confirming their worst fears, in AD 39 Caligula announced the revival of the treason trials, the bloodthirsty trials which had given an air of terror to the latter years of Tiberius' reign.

Caligula also kept his favourite racehorse, Incitatus, inside the palace in a stable box of carved ivory, dressed in purple blankets and collars of precious stones. Dinner guests were invited to the palace in the horse's name. And the horse, too, was invited to dine with the emperor. Caligula was even said to have considered making the horse consul.

Rumours of disloyalty began to reach an ever more deranged emperor. In the light of this a recently retired governor of Pannonia was ordered to commit suicide.

Then Caligula considered plans to revive the expansionist campaigns of his father Germanicus across the Rhine. But before he left Rome he learnt that the army commander of Upper Germany, Cnaeus Cornelius Lentulus Gaetulicus, was conspiring to have him assassinated.
In spite of this Caligula in September AD 39 set out for Germany, accompanied by a strong detachment of the praetorian guard and his sisters Julia Agrippina, Julia Livilla and Marcus Aemilius Lepidus (widower of Caligula's dead sister Julia Drusilla).
Soon after he had arrived in Germany not only Gaetulicus but also Lepidus were put to death. Julia Agrippina and Julia Livilla were banished and their property seized by the emperor.

The following winter Caligula spent along the Rhine and in Gaul. Neither his planned German campaign nor a proposed military expedition to Britain ever took place. Though there are reports of his soldiers being ordered to gather shells on the shore as trophies for Caligula's 'conquest of the sea'.
Meanwhile, a terrified senate granted him all kind of honours for his imaginary victories.

It comes as no surprise then that at least three further conspiracies were soon launched against Caligula's life. Were some foiled, then alas one succeeded.
Caligula's suspicion that his joint praetorian prefects, Marcus Arrecinus Clemens and his unknown colleague, were planning his assassination prompted them, in order to avoid their execution, to join a part of senators in a plot.
The conspirators found a willing assassin in the praetorian officer Cassius Chaerea, whom Caligula had openly mocked at court for his effeminacy.

In 24 January AD 41 Cassius Chaerea, together with two military colleagues fell upon the emperor in a corridor of his palace.
Some of his German personal guards rushed to his aid but came too late. Several praetorians then swept through the palace seeking to kill any surviving relatives. Caligula's fourth wife Caesonia was stabbed to death, her baby daughter's skull smashed against a wall.

The scene was truly a gruesome one, but it freed Rome from the insane rule of a tyrant.